Bilateral vs. unilateral electromyographic examination of the external anal sphincter muscle.

AIM OF THE STUDY: In patients with cauda equina or conus medullaris lesions, bilateral electromyographic (EMG) examination of the subcutaneous external anal sphincter (EAS) muscles has been suggested. In spite of its circular shape, EAS should be considered as two separate semicircular muscles. The aim of the present study was to test the hypothesis that information obtained by bilateral examination of the EAS muscle outweighs inconvenience due to additional needle insertions. PATIENTS AND METHODS: A group of 67 patients with clinical and radiological data supportive of cauda equina or conus medullaris lesion was studied. From the subcutaneous EAS muscles motor unit potentials (MUPs) were sampled by the standard concentric EMG needle electrode, and an advanced EMG system with template operated multi-MUP analysis. Severity of EMG abnormalities was determined, and compared in 48 pairs of the left/right subcutaneous EAS muscles. RESULTS: In 18 patients, bilateral EMG abnormalities were found, in five of them asymmetry of involvement was demonstrated. Unilateral MUP abnormalities were found in 22 patients. The sensitivity of unilateral EMG analysis was 57% and of bilateral examination, 83%. CONCLUSION: In patients with suspected cauda equina lesions, as a rule, bilateral EMG of the subcutaneous EAS muscle is recommended.     

Saddle sensation is preserved in a few patients with cauda equina or conus medullaris lesions1

Although saddle sensory deficit seems the most useful clinical sign in the diagnosis of a cauda equina or conus medullaris lesion, findings of previous studies were controversial. The aim of the present study was to try to resolve this issue. The data from the author's series of patients with clinical, electrodiagnostic and radiological findings compatible with a cauda equina lesion were reviewed. Of the 117 patients in the series, 11 (10 men) did not have a saddle sensory deficit. These 11 patients had less severe sacral dysfunction than the others, and none of them needed urgent surgical intervention. They all had electromyographic (EMG) signs of a significant motor fibre lesion, and in seven men the sacral (penilo‐cavernosus) reflex was clinically abnormal. The study revealed normal saddle sensation in approximately 10% of patients with cauda equina or conus medullaris lesions. Dissociation between preserved touch sensation and abnormal EMG findings, as well as dissociation between preserved touch sensation and a non‐elicitable penilo‐cavernosus reflex might be explained by preservation of the thinner sensory nerve fibres, which are more resistant to compression. Although, saddle sensory loss seems to identify patients who might benefit from urgent spinal imaging and surgery, further diagnostic evaluation is also indicated in patients with normal saddle sensation, particularly due to the increased frequency of spinal tumours found in this subgroup.     

Bowel dysfunction in patients with cauda equina lesions

Despite their serious sequels on bowel function, lesions of the cauda equina have not been previously systematically studied in larger patient populations. This was the aim of the present report. From the registrars of a diagnostic and rehabilitation centres 67 patients with clinical, electrodiagnostic and radiological findings supportive of the cauda equina lesions were recruited. The Slovene versions of the standard questionnaires for anal incontinence and constipation were used. The responses were scored, impairments categorized and previous treatments noted. Neurological examination, electromyography (EMG) of lumbo-sacral myotomes, quantitative anal sphincter EMG and electromyographic evaluation of the sacral reflex were performed. Severe anal incontinence/constipation was reported by 18%/0%, moderate by 36%/33%, and slight by 28%/43% of our patients. Twenty-one per cent of patients wore pads continuously and 14% occasionally. More than half of the patients (60%) reported changes in their lifestyle due to anal incontinence. No patient had completely normal findings on neurological examination. Perianal sensory loss correlated ( P  < 0.05) with anal incontinence and gender with constipation (women >men). Only two patients had received medical attention for bowel dysfunction. Study thus demonstrated significant bowel impairment in patients with lesions of the cauda equina, which has received insufficient medical attention.     

神经电生理监测技术在圆锥马尾病变手术中的应用

目的探讨神经电生理监测技术在圆锥马尾病变手术中应用价值。方法回顾性分析110例圆锥马尾病变患者临床资料,其显微外科手术均在神经电生理监测下进行,感觉诱发电位(somatosensory evoked potential,SEP)和运动诱发电位(motor evoked potential,MEP)监测脊髓功能,肌电图(electromyography,EMG)确定肿瘤切除范围。结果显微镜下病变全切除92例(83.6%),次全或大部分切除18例(16.4%)。术后随访1~58个月,神经系统查体及JOA评分发现脊髓神经功能改善102例(92.8%),无变化4例(3.6%),下降4例(3.6%)。对病变切除前与切除后SEP潜伏期和波幅以及MEP潜伏期进行自身比较,脊髓神经功能改善和下降患者电生理监测指标改变差异有统计学意义(P0.05),脊髓神经功能无变化患者相关监测指标改变差异无统计学意义(P0.05),神经电生理监测指标的变化与术后脊髓神经功能改善情况基本相吻合。结论术中神经电生理监测可以实时了解脊髓神经功能的完整性,结合显微神经外科技术可以明显提高圆锥马尾病变的全切率,减少术后并发症,提高手术疗效及安全性。     

Epidemiology of cauda equina and conus medullaris lesions

The epidemiology of cauda equina and conus medullaris lesions is not well known, and this study aimed to provide further information on this topic. In the period 1996-2004, patients fulfilling the clinical, electrodiagnostic, and radiological criteria for such lesions were identified. For cauda equina/conus medullaris lesions an annual incidence rate of 3.4/1.5 per million, and period prevalence of 8.9/4.5 per 100,000 population were calculated. The values obtained are probably valid estimates of the incidence and prevalence of these lesions in developed countries.     

Ependymal cyst in the lumbar spine associated with cauda equina compression.

There are many reports of extradural ependymal cysts in the literature; however, reports of intradural ependymal cysts are very rare and there has been no prior mention of an ependymal cyst originating from the filum terminale. In this report we present the case of a 31-year-old woman with an ependymal cyst that caused cauda equina compression, and discuss the clinical profile of the case in terms of symptoms, diagnostic images, pathohistological findings, and surgical procedures. To our knowledge, this is the first report of an ependymal cyst that caused cauda equina compression. The cyst was successfully treated by excision of the cyst during careful intraoperative monitoring to prevent neurological damage to the conus medullaris and cauda equina.     

Sexual dysfunction after spinal cord or cauda equina lesions

In the neurological follow-up 68 patients with a history of spinal cord or cauda lesions of different aetiology and in different stages of regression were examined and interviewed concerning pre- and postmorbid sexual function. As to sexual dysfunction there was no difference between men and women. There was little relationship between the patients' motor function and their present sexual activity. On the other hand there was a statistically significant relationship between bladder dysfunction and sexual dysfunction. In elderly patients sexual activity was often reduced and also in cases of complete neurological restitution. Stability of the patients' marriage was as in the population on the whole. It is concluded that not only young patients, but also elderly ones, had a need for sexual rehabilitation after treatment for spinal cord or cauda equina lesion.     

Evaluation and treatment of autonomic disorders of the urogenital system

Autonomic pathways are important in the regulation of both lower urinary tract and sexual function, and their interruption in neurological pathologies predictably results in variable urogenital dysfunction, depending mainly on the level of the lesion. A normal neurological examination of a patient with urogenital complaints should exclude an underlying neurological pathology, and the neurologist should become involved in the management of symptoms. Electromyography can be of value in the diagnosis and management of cauda equina lesions and multiple system atrophy, but neurophysiological investigations are of no importance in the diagnosis of neurogenic sexual dysfunction. Urodynamic studies have proven helpful in determining the type and management of lower urinary tract dysfunction. Oral anticholinergics usually combined with clean intermittent catheterizations are the first-line treatment options for neurogenic lower urinary tract dysfunction, with intravesical treatments emerging as the main alternative in intractable incontinence. The availability of effective oral phosphodiesterase inhibitors has revolutionized the management of erectile dysfunction, but treatment of ejaculatory and orgasmic disorders as well as of female sexual dysfunction still remains problematic.     

Infarction of the conus medullaris

We encountered a patient with acute cauda equina syndrome. The clinical course, laboratory data and imaging study, including magnetic resonance imaging (MRI) strongly suggested that this episode was caused by a vascular disorder of the conus medullaris. We emphasized the diagnostic usefulness of MRI in the vascular disease of the conus medullaris as well as the clinical importance of this disease in the differential diagnosis of acute cauda equina syndrome.     

Myxopapillary ependymoma of the conus medullaris presenting with intratumoral hemorrhage during weight lifting in a teenager

Intratumoral hemorrhage within a myxopapillary ependymoma of the conus medullaris and cauda equina is rare. Most patients with myxopapillary ependymoma present insidiously, but they may present with hemorrhage or cauda equina syndrome. Limited number of case reports available has described this condition only in adult patients. We report our experience with intratumoral hemorrhage of myxopapillary ependymoma of the conus medullaris during weight lifting in a 15-year-old boy.     

Study of the effects of flexion on the position of the conus medullaris

BACKGROUND: Previous anatomic studies have shown the conus medullaris to terminate between T12 and L1 vertebral levels in adults with normal spinal anatomy. Prior anatomic and radiographic studies of conus position with flexion and extension of the spine have had conflicting results. We performed a cadaveric study with direct visualization of the conus during flexion and extension to further study this question and potentially determine if flexion and extension of the spine during magnetic resonance imaging may prove to be a diagnostic tool in such pathologies as occult tethered cord syndrome. MATERIALS AND METHODS: We performed T12 to L3 laminectomies in five fresh adult cadavers and exposed the conus and cauda equina. Cadavers were fully flexed at the waist and neck and the conus position observed. RESULTS: In all specimens, the conus terminated between T12 and L1 in the prone position. During flexion, the conus position remained stable with no ascent. However, flexion produced stretching and medial displacement of the cauda equina. CONCLUSIONS: Flexion of the spine does not cause the conus medullaris to change position in fresh human cadavers; however, flexion does cause the cauda equina to stretch and displace medially over the conus. Therefore, it is unlikely that the conus would change position during spine flexion during imaging or procedures such as lumbar puncture.     

Combination of caudal myxopapillary ependymoma and dermal sinus: a single shared embryologic lesion?

A female child presenting with acute flaccid paraparesis at 18 months was found to have a dermal sinus in combination with a dermoid cyst and a myxopapillary ependymoma of the cauda equina and conus medullaris. A possible embryologic relation between these lesions is discussed.     

椎管内圆锥马尾区畸胎瘤的治疗

目的 总结椎管内圆锥马尾区畸胎瘤的临床特点和治疗经验。方法 回顾性分析1997年8月至2017年7月手术治疗的51例椎管内圆锥马尾区畸胎瘤的临床资料。结果 肿瘤的囊性部分全切除46例,次全切除加囊壁电灼5例;肿瘤实性部分全切除5例,次全切除20例,大部切除26例。51例术后病理检查均为成熟性囊性畸胎瘤。术后发生脑脊液漏3例、泌尿系感染5例,均治愈。32例疼痛中,24例术后疼痛缓解或消失,8例无变化。12例运动障碍中,7例术后肌力提高1~3级,4例无变化,1例肌力下降。7例括约肌功能障碍中,4例改善,3例无变化。51例术后随访6个月~19年,平均7.8年,随访超过5年27例。按McCormick分级标准,脊髓功能好转39例,不变11例,恶化1例。随访期间,未见肿瘤复发。结论 椎管内畸胎瘤多分布于脊髓圆锥马尾区,以慢性脊髓及神经压迫为表现。手术应在显微镜下,尽量全切肿瘤的囊性部分,如有囊壁残留应电灼防止复发,对肿瘤的实性部分应在避免脊髓损伤情况下,尽量切除减压,手术疗效满意。     

Cauda equina syndrome complicating pneumococcal meningitis

A 14-month-old female with pneumococcal meningitis presented with flaccid paraplegia, saddle anesthesia, and bladder and bowel dysfunction. Magnetic resonance imaging of the spine demonstrated intense gadolinium enhancement of the cauda equina, whereas the conus medullaris appeared normal. This finding indicated that lumbosacral polyradiculopathy caused her symptoms.     

The syndrome of acute anterior lumbar spinal cord injury

This is a presentation of 3 patients who manifested with the clinical syndrome of anterior spinal cord injury at the lumbar level. A combined injury of conus medullaris and cauda equina in this particular level of the cord between T12 to L2 spines makes clinical assessment difficult leading to a false diagnosis of "cauda equina injury". Careful studies of the ventral cord of the conus medullaris are needed to confirm a contusion, hematomyelia or compression. Basis for theoretical presence of lumbar anterior cord syndrome as well as clinical diagnosis are discussed.     

Cystic mature teratoma of the filum terminale in an adult. Case report and review of the literature

Intradural spinal teratoma is a very rare entity, more prevalent in childhood, that may associate with dysraphic defects. The authors report a 46 years old man with a cauda equina syndrome and an L1-2 tumor. An L1-2 laminectomy was performed and a mass was resected at the base of the filum terminale, which was in contact with the conus medullaris. Histopathological diagnosis was of cystic mature teratoma. Spinal teratomas may be found anywhere along the spine, but are more frequent in the cauda equina. We discuss the origin of these tumors and review the literature concerning these lesions.     

Bulbocavernosus reflex in patients with conus medullaris and cauda equina lesions.

The clinical value and practical application of the electrically induced BC reflex was investigated in 40 patients with traumatic or compressive lesions of the conus medullaris or cauda equina. It was shown that the BC reflex was either absent or delayed depending upon the invovlement of the sacral 2--4 spinal and radicular segments. The latency of the BC reflex was normal in patients with mainly epiconus and lumbar cord involvement. The loss of the BC reflex in the acute period of traumatic lesions was an adverse prognostic sign while the presence of the reflex whether or not delayed, indicated a more benign final outcome of sphincter and sexual reflex disturbances. In chronic progressive compression, the latency of BC reflex was often delayed.     

Sparganosis presenting as a conus medullaris lesion: case report and literature review of the spinal sparganosis

BACKGROUND: Sparganosis is a rare parasitic infection affecting various organs, including the central nervous system. In rare cases, sparganosis may involve the spinal cord, usually at the thoracic area. We herein report, to our knowledge, the first case of sparganosis presenting as a conus medullaris lesion and review the literature of sparganosis involving the spinal cord. OBSERVATION: A 42-year-old man presented with progressive perianal paresthesia and sphincter disturbances. Results of enzyme-linked immunosorbent assay of the cerebrospinal fluid and surgical biopsy were consistent with sparganum infection affecting the conus medullaris. We reviewed 7 other cases of spinal sparganosis. CONCLUSIONS: Sparganosis may present as a conus medullaris lesion. This possibility should be considered when clinicians encounter patients with a conus medullaris lesion or cauda equina syndrome with uncertain diagnosis.     

Colorectal transport during defecation in patients with lesions of the sacral spinal cord

Normal defecation involves reflexes between the colorectum and sacral spinal cord. Lesions of the conus medullaris or cauda equina interrupt such reflex arches and cause constipation. The aim of the study was to compare colorectal transport during defecation in patients with sacral spinal cord lesions and healthy volunteers. Ten patients with sacral spinal cord lesions (six men and four women, age 21-57 y, median = 36) and 16 healthy volunteers (10 men and six women, age 22-42 y, median = 30) took one or two doses of 111In-labelled polystyrene pellets perorally to mark colorectal contents. Abdominal scintigraphy was performed before and after defecation. Total colorectal emptying and segmental antegrade or retrograde transport was computed. Median colorectal emptying during normal defecation was 81% of the rectosigmoid (range: 53% of the rectosigmoid to complete emptying of the rectosigmoid and 40% of the descending colon) in healthy volunteers and 27% of the rectosigmoid (range: 0-44% of the rectosigmoid) in patients with conal/cauda equina lesions (P < 0.001). Median antegrade transport was 82% (control group) vs 27% (patients) of the rectosigmoid (P < 0.001), 38% vs 4% of the descending colon (P < 0.02), 13% vs 1% of the transverse colon (P = 0.28), and 4% vs 2% of the caecum/ascending colon (P = 0.76). It is concluded that damage to reflex arches between the colorectum and the sacral spinal cord significantly reduces emptying of the rectosigmoid and descending colon during defecation.     

Post-irradiation polyradiculopathy mimics leptomeningeal tumor on MRI

Three patients with a remote history of Hodgkin's disease treated with total or subtotal lymphoid radiation 17 to 24 years earlier developed lumbosacral polyradiculopathy associated with nodular meningeal enhancement of the conus medullaris and cauda equina on MRI. None had evidence of recurrent Hodgkin's disease or second malignancy, and the MRI findings may be sequelae of radiation therapy.